City may need second sewer plant

Lebanon may need to add a "second treatment plant" to ease its ongoing wastewater woes in addition to making several other improvements, though the cost of the potential projects remain unknown, an official says.
Public Works Commissioner Jeff Baines told city councilors in a Feb. 24 memo "more peak flow sewage capacity must be provided" for the "aging sanitary sewer system" that serves Lebanon.
"Some of that capacity may be in the form of a second treatment plant in another location," Baines' memo said, adding the city may require additional "storage capacity to capture and detain peak flows before they can overflow."
"In order to pump the increased treatment plant capacity to the river, a new effluent discharge pipeline to the Cumberland River will have to be built," the memo added.
However "associated budget costs" for possible projects remain unknown, Baines said in the document.
"The exact dimensions of those possible projects have not been determined," the memo said. "Studies are presently underway to characterize the quantity of the existing overflow. Once that is complete, solutions can be more accurately proposed along with the associated budget costs."
In the document Baines said solutions to the city's wastewater woes won't be in place until June 2010.
"It is not economically feasible to replace the failing system all at once. Replacement will need to come, but over a longer period of time so that the costs can be spread out," Baines said in the memo to city councilors and Mayor Don Fox, copies of which were supplied to local news organizations.
Baines prepared the memo in response to a letter from Ward 3 City Councilor William Farmer questioning the city's recent wastewater woes, which have been highlighted by an ongoing criminal investigation of the sewage treatment plant on Hartmann Drive.
In a separate letter to Farmer, Baines suggested the city councilor attend a Feb. 28 session of the city's Public Works Committee where he said a "draft" of the city's five-year plan for sewer improvements will be presented.
In the memo to the full Council, Baines said the city's sewer problems "are not unique," maintaining "overflows during rainfall events" are "a near universal characteristic of aging sanitary sewer systems throughout the nation and the world."
He noted the city's sewage system was built "before the advent of modern plastic gasketed sewer pipes" and said leaks created by age – on private property as well as in city maintained lines – are the root of Lebanon's wastewater woes.
"When it rains, rainwater soaks into the ground and leaks into millions of sewer pipe cracks," Baines said in the memo. "When this happens, the normal flow of the sewer pipe, which might normally be one-fourth full, becomes flooded with unwanted rain water. It is not uncommon for municipal sewer systems to experience an increase in flow of five times normal after a heavy or prolonged rainfall."
He estimated such "excess flow" is made up "of about three-fourths rainwater and one-fourth sewage" and treatment plant operators "have no control over this overflow other than maximizing the flow treated through the plant."
"Except for during heavy rain events, the treatment plant is not overloaded and routinely meets all state and federal requirements," Baines' memo said.
The public works commissioner maintained Lebanon has already finished four of six major reports required by an agreed order it entered into with the state Department of Environment and Conservation last August setting out "a schedule for correction of the overflow problem."
Even before the agreement, Baines said, the city was working "aggressively" toward a solution to its overflow problems, listing a number of projects workers have already completed including "manhole inspection and repairs."
"Lebanon's aging sanitary sewer system is the source of the problem," Baines said in the memo.
The public works chief also said officials do not feel a joint TDEC/TBI investigation of the sewer plant is related to the the city's "overflow problem" and repeated earlier assurances the town's drinking water supply remains safe.
Senior Staff Writer Brooks Franklin can be reached at 444-3952 ext. 14 or by e-mail at brooks.franklin@lebanondemocrat.com.